Stainless Steel E312
EN E312 · UNS W31310
E312 is a 29Cr-9Ni covered electrode (UNS W31310) whose high-ferrite duplex deposit is the standard choice for welding unknown, dissimilar or hard-to-weld steels, with -15, -16 and -17 coatings for SMAW and matching ER312 wire for GTAW/GMAW.
Reference datasheet — E312 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the AW condition
E312 tempers and conditions
E312 is supplied in 4 conditions, soft to hard. AW is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Rutile-silicate (acid-rutile) coated electrode, AC or DCEP | Choose for the finest bead appearance and lowest spatter on sheet and cosmetic repair work; slightly more fluid slag than -16. | 570 | 770 | 26 | 22 HRC | 2.2 % IACS |
Lime (basic) coated electrode, DCEP only | Pick for maximum weld-metal cleanliness/toughness and out-of-position root runs on heavy or highly restrained joints; DC only, requires redrying. | 575 | 770 | 28 | 21 HRC | 2.2 % IACS |
AWDefault As-welded deposit | Standard supplied/used condition: deposit tested and used in the as-welded state with 30–45 FN ferrite. | 580 | 780 | 26 | 22 HRC | 2.2 % IACS |
Rutile (titania) coated electrode, AC or DCEP | Most widely stocked coating type: smooth arc, easy slag removal, all-position, runs on small AC or DC sets. | 580 | 780 | 25 | 22 HRC | 2.2 % IACS |
Supply forms, finishes and certifications
Ways E312 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
ER312-WIRE | ER312 bare wire deposit | Supply form |
What is E312?
E312 is a 29Cr-9Ni covered electrode (UNS W31310) whose high-ferrite duplex deposit is the standard choice for welding unknown, dissimilar or hard-to-weld steels, with -15, -16 and -17 coatings for SMAW and matching ER312 wire for GTAW/GMAW. As-welded strength is high at about 580 MPa yield, 780 MPa tensile, 26 % elongation and 240 HB (22 HRC), and the deposit tolerates heavy dilution when buttering. Ferrite content limits service to about 300 °C because of embrittlement, and the weld metal is magnetic and poorly suited to cold work. For elevated-temperature dissimilar joints use E309 or E310 instead. E312 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F). E312 has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 26% and the elastic modulus is 200 GPa (29 Msi).
What is E312 used for?
- dissimilar steel joints
- repair welding of unidentified alloys
- buffer/butter layers
- cast steel repair
Advantages
- Readily welded — 90/100, better than 95% of stainless steel grades
- High strength — 580 MPa (84.1 ksi), better than 86% of stainless steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
- Hard to polish — 55/100, worse than 89% of stainless steel grades
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 88% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
E312 properties
Typical room-temperature values for E312-AW; bars are the position among stainless steel grades.
Physical3
E312 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical17
E312 has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 26% and the elastic modulus is 200 GPa (29 Msi).
Thermal5
E312 is rated for continuous service to 300°C (572 °F). It conducts heat at 15.5 W/m·K (8.96 BTU/hr·ft·°F), better than 53% of stainless steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
E312 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 52% of stainless steel grades.
Sustainability4
Producing a kilogram of E312 takes about 60 MJ of energy and emits 5.2 kg of CO₂ — more than 70% of stainless steel grades. Typical recycled content is 55%.
Manufacturability6
E312's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability excellent (90/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. E312 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with E312
Is E312 easy to machine?
Hard, work-hardening duplex deposit — grind or use rigid setups with sharp carbide, low speed and heavy positive feed; avoid dwelling.
Can E312 be welded?
Weld with low heat input and stringer beads, interpass below ~150 °C, usually no preheat and no PWHT; redry electrodes (‑15 types especially) before use and keep dilution moderate to preserve ferrite and crack resistance.
Can E312 be formed, bent or molded?
Not a wrought product form — the deposit is high-strength and low-ductility, so cold straightening or bending of 312 weld metal is not recommended.
E312 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CAWS A5.4 max | ≤ 0.15 | 0.1 |
| Cr | 28 – 32 | 29.5 |
| Ni | 8 – 10.5 | 9 |
| Mn | 0.5 – 2.5 | 1.5 |
| Si | ≤ 0.9 | 0.6 |
| Moresidual | ≤ 0.75 | |
| Curesidual | ≤ 0.75 | |
| P | ≤ 0.04 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on E312?
Grind and pickle/passivate to remove slag and heat tint; the ferrite-rich weld is magnetic and etches differently from austenitic base metal, giving a visible colour/contrast line after polishing.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel E312 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- W31310
- Also called
- AWS A5.4 E312
How much does E312 cost?
E312 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
E312 — frequently asked
What is E312 used for?
E312 is typically used for dissimilar steel joints, repair welding of unidentified alloys, buffer/butter layers and cast steel repair. In short: welds unknown steels; high-ferrite crack resistance; low-temperature service only.
What is the yield strength of E312?
E312 has a typical yield strength of 580 MPa (84.1 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 86% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is E312 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Hard, work-hardening duplex deposit — grind or use rigid setups with sharp carbide, low speed and heavy positive feed; avoid dwelling.
Can E312 be welded?
Yes — weldability is rated excellent (90/100). Weld with low heat input and stringer beads, interpass below ~150 °C, usually no preheat and no PWHT; redry electrodes (‑15 types especially) before use and keep dilution moderate to preserve ferrite and crack resistance.
What surface finishes work on E312?
Grind and pickle/passivate to remove slag and heat tint; the ferrite-rich weld is magnetic and etches differently from austenitic base metal, giving a visible colour/contrast line after polishing.
Can E312 be formed, bent or molded?
Not a wrought product form — the deposit is high-strength and low-ductility, so cold straightening or bending of 312 weld metal is not recommended.
What is the maximum service temperature of E312?
E312 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between E312-AW and E312-17?
AW is the default condition — standard supplied/used condition: deposit tested and used in the as-welded state with 30–45 FN ferrite. E312-17: choose for the finest bead appearance and lowest spatter on sheet and cosmetic repair work; slightly more fluid slag than -16. Yield strength is 580 MPa in AW versus 570 MPa in E312-17.
How much does E312 cost?
E312 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- AWS A5.4/A5.4M — Specification for Stainless Steel Electrodes for Shielded Metal Arc Welding — American Welding Society (2012)
- AWS A5.9/A5.9M — Bare Stainless Steel Welding Electrodes and Rods (ER312) — American Welding Society (2017)
- GB/T 983 (A302/A307) (2012)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (stainless weld metal) — ASM International (1993)
- 312-type SMAW electrode datasheets (ESAB, Lincoln Electric, Böhler Welding) — various (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.